The present invention relates to a fuel injector with piezoelectric actuator.
Fuel injectors with piezoelectric actuators have been available for many years now, i.e. fuel injectors provided with a valve that is displaced in a working direction between a closed position and an open position for activating a piezoelectric actuator.
Known piezoelectric actuators, for example of the type described in patent application DE19909451, comprise a fixed frame and an actuator body made of piezoelectric material arranged in alignment with a working direction; the actuator body has a lower base, which is arranged close to the valve, is mechanically linked to the valve itself, and is free to slide with respect to the fixed frame in the working direction, and has an upper base, which is opposite the lower base and is linked to the fixed frame. In use, the actuator body is excited with an electrical field in order to cause it to expand in the working direction and therefore displace the valve in the working direction from the closed position to the open position, in a direction in accordance with the fuel outlet direction. However, such a structure requires that in order for the valve to move from the closed position to the open position, it is displaced towards the outside of the injector putting itself into a configuration that can cause the injector to be soiled, and therefore its functions impaired.
The objective of the present invention is to produce a fuel injector with piezoelectric actuator, which does not have the drawbacks described above and, in particular, is easy and inexpensive to implement.
According to the present invention, a fuel injector with piezoelectric actuator is produced in accordance with claim 1.